The surface hardness of grinding balls define on two diametrically opposite platforms. In determining, the hardness at each platform perform four measurements. The first three measurements performed at the vertices of imaginary equilateral triangle with a side length from 6 to 8 mm. These measurements are tentative and the results are not recorded in the test report. The fourth measurement carried out in the center of the triangle (Picture 1). The result of this measurement recorded in the test report. Picture 1. Execution scheme the hardness measurements on each platforms of grinding ball Hardness of the grinding ball defined as the average value of measurements both surfaces. Hardness batch of grinding balls defined as average value of hardness 10 of grinding balls selected from the batch. For confirmation the grinding ball to the 4th group of hardness carried out further hardness measurement at depth 1/2 radius of the grinding ball. At distance of 1/2 radius perform four hardness measurements on two mutually perpendicular lines. The minimum and the maximum hardness values ignore, and the hardness defined as arithmetic average value of the other two dimensions (Picture 2). Picture 2. Execution scheme the hardness measurements on platforms of grinding ball (distance […]
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Hardness of steel grinding balls determined on attorneys devices. The hardness measurement of grinding balls carried out at room temperature. The support surface of the table, instrument stands must be free from foreign matter (scale, grease, etc.). In the measurement of hardness must be met these conditions (pic. 1): Gradual bringing a tip into contact with the working surface of the ball; Gradual application of preliminary force F0 and the main force F1 (for 2-8 sec); Gradual removal the main forces F1 through 1-3 sec after a sharp slowing or stopping of the indicator arrows. Picture 1. Schematic of the hardness measuring by Rockwell method (where, F0 – preliminary force, H (kgf); F1 – the main force, H (kgf); F – the total force F0 + F1, H (kgf)) The distance between the centers of two adjacent imprints must be not less than four imprint diameters (but not less than 2 mm). Rockwell hardness value determined on a scale indicator durometer rounded to 0.5 unit of hardness. For measuring a surface hardness of the grinding ball perform two diametrically opposite platforms, as shown in Picture 2. Picture 2. Platform preparation for measuring the hardness of the ball Ø40mm For compliance […]
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Company Energosteel cares primarily about the quality of produced grinding balls. That’s why we continue to complement our test laboratory with the necessary equipment. Thus, the test laboratory has acquired a portable conductivity meter PWT. This device is equipped with a built-in electrode for determining the electrical resistance of the distilled water in the cooling circuit of induction furnaces. Control of the electric resistance of distilled water in the cooling circuit of induction furnaces is necessary for the stable operation of the furnaces during heating billet before the helical rolling and eventually for obtaining consistent quality of grinding balls for drum mills.
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According to the requirements of GOST 9013-59 the roughness of the sample surface (or surface area) for measure hardness of the product Ra should not exceed 2,5 mm, unless otherwise specified in the standard technical documentation for metal. The sample should be prepared in such a way that its properties have not changed as a result of mechanical or other treatment. Grinding on the surface grinder is the best way of preparation the grinding ball surface for hardness measure. Grinding machine designed for the effective conduct of grinding the metal details by special abrasive tool (grinding wheels). Metal details fixed on a table of surface grinder. For grinding balls done special matrix, it placed from 2 to 5 pieces, depending on the diameter of the balls. The grinding balls grinded simultaneously. A working cutting movement consists as follows – the fixed grinding balls on a table in a matrix moved relative to the cutting tool and thus occurs machining surface abrasive balls. Surface grinding includes the following working movements: cutting tool rotation, longitudinal and transverse feed ball, ball move toward cutting grinding wheel. In the grinding, place of contact the ball with grinding wheel fed coolant, because it helps prevent […]
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Grinding media is the main component in the technological process of grinding materials for cement production, electric power, glass, silicate products, at the extraction of the concentrate for the production of metals. It should be noted, the price cannot be the only determining factor for choosing a supplier of grinding media. By choosing a supplier, cement enterprises and mining companies increasingly focused on reducing specific consumption of grinding media per ton of produced product in monetary terms, that is the optimal ratio of the specific consumption and prices for grinding media. In order to select the right supplier of grinding media, needs to understand the applied production technology, as well as to understand exactly what kind of grinding media required in the particular case (geometry, the material of the grinding media and technical parameters – hardness). International experience shows that using the steel grinding balls (instead cylpebs, cylinders, ellipsoids) of alloy high carbon steel in the cement industry (for grinding clinker and limestone) and mining industry (1st, 2nd and 3rd stage of grinding in concentration of ore) provides significant economy by reducing specific consumption and saving electricity consumption. Compared with others, the specific consumption by the application of grinding balls […]
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Grinding of minerals are carried out in the mills. There are different types of the grinding media used in grinding. According to the geometric shape of grinding media there are: The balls of different diameters; Short cylinders – steel circle cut into the size; Steel bars (round billet); Truncated cones (cylpebs, ellipsoids). The material used for the production of the grinding media can be divided into three main groups: Steel grinding media – used carbon steel as a raw material for the production, which doped with various chemical elements to impart grinding medias properties as hardness and strength. Cast iron grinding media – for the production this type of the grinding media used cast iron as “gray” and “white.” The ceramic grinding media – this type of the grinding media, as the name suggests, is made of ceramic and used mainly in small-sized mills (about 50 liters) in the chemical and food industries. According to the production method, grinding media (except for the rods of short cylinders) are divided into: Today, in industry for crushing the material mainly used the grinding media, which have a geometrical shape of a ball or a truncated cone (hereinafter – cylpebs). Consider in more […]
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The activity of “Energosteel” company associated with the need to deliver the goods – grinding balls, raw materials and components. In many cases, the cost of delivery has quite a large share of the company’s total costs, so the optimization of these expenses paid a great attention. Logistics of our company is an integrated process designed to promote the creation of customer value with the lowest total cost, customer satisfaction of our grinding balls and facilitate production and marketing activities. Logistics and customs clearance department of company «Energosteel» chooses the best route and the type of vehicle for delivering grinding balls worldwide. Grinding steel balls for ball mills can be delivered in bulk or in big bags, in barrels or containers or though another most effective means for the customer. In calculating the cost of the delivery the grinding balls, experts of Energosteel consider not only the price segment of the shipping cost, but also customer requirements for the method of delivery (type and specifications of the vehicle) that may affect the safety of goods on the route and the speed of its acceptance and / or unloading, which reduces delivery costs. One example of an individual approach to the […]
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The company “Energosteel” has produced grinding balls 30 mm (volume – 150 tons) of high carbon alloy steel in early October 2016. This party of grinding balls showed higher hardness values throughout cross section of the ball with a surface hardness 65-66HRC and volumetric hardness – 64-65 HRC. According to an old national quality standard for steel grinding balls (3499-97) and to a new national quality standard for steel grinding balls (DSTU 8538: 2015) these products comply with the fifth group of hardness. Grinding balls have been successfully tested for the impact resistance. Thirty balls have been selected from a batch for the experiment. Each selected ball sustained the total impact energy of 64 312 J without destruction. This party of steel grinding balls for ball mill will be shipped in the nearest future to the Middle East market.
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The company “ENERGOSTEEL” completed the industrial test of grinding balls 40 mm of the fifth group of hardness (DSTU 3499-97) on the base of one of the largest manufacturers of aerated concrete in Azerbaijan in August 2016. Tests were carried out over one year, which minimized the impact of various factors that have an influence on the specific consumption of grinding media (for example, the performance of the ball mill, the quality of raw materials, etc.). Analysis of the results of a sufficiently long period of testing has shown that the difference in the consumption of steel grinding balls of the fourth and fifth groups of hardness was more than 20%. Based on obtained result, the management of the partner company decided to permanently use grinding balls 40 mm of the fifth group of hardness (DSTU 3499-97) produced by “Energosteel”.
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Participation of company representatives in the largest specialized exhibition of mining industry in the Middle East, North and East Africa. New sales markets for grinding balls of Energosteel. 25-26 of October 2016 Energosteel took part in vitally important event for global mining industry – The MENA Mining Show in Dubai, UAE. Exhibition was held in Dubai World Trade Centre. The MENA Mining Show is the largest and possibly the most significant mining exhibition in the Middle East and Africa. For the past 9 years, the event has become the great marketplace to show, sell and buy the latest mining technologies, equipment and services. Over 2000 visitors, near 100 governmental officials, 150 leading mining companies, investors, and key solution providers to build sustainable relationships in the Middle East and Africa’s mining industry, attended the event. For us primarily was important that representatives of global companies – direct consumers and the world’s largest suppliers of grinding balls, visited the exhibition. The main sales market for the grinding media in the Middle East and Africa includes enterprisesof non-ferrous metallurgy, chemical industry, as well as companies, mining and processing of organic and inorganic minerals. We had pleasure to meet principal officers of UAE, Saudi, […]
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The ball mill is a hollow drum closed with loading and unloading end caps, filled with grinding media and rotated around its axis. The drum of the ball mill (Pic. 1) is a hollow cylinder of steel, lined inside with armor lining plates which protect it from impact and friction effects of the balls and the grinding material. The shape of drum liners has a significant impact on mill’s work. Drum Liners of ball mills operated on a large source material have ribs. For mills operated on the fine materials use lining with small ribs or quite smooth. Height, mutual arrangement and shape of the ribs define force of adhesion the grinding media with the drum and the results of the mill’s work. It is important when the character of the lining surface did not change harshly during its deterioration. Pic.1. The drum of the ball mill End caps molded integrally with the hollow pins. On pins planted supporting bandages. The drum is supported by two self-aligning roller through these bandages. Material loaded into the mill through the hopper. The mill is driven by a motor through a clutch, gearbox and flexible coupling. Grinding media followed to the direction of […]
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“Energosteel” сompany successfully tested an experimental batch of 100mm balls on the impact resistance. This kind of grinding balls manufactured from high carbon alloy steel and correspond to the fifth group of hardness according to DSTU 8538: 2015. Fifty balls have been selected from a batch for the experiment. The tests on the impact resistance performed using a drum kit (named the Koper) of the vertical type. The operating principle of the Koper based on definition expended operation for destruction of the grinding ball by a free fall hammer (load with certain weight). As a result of the test, each selected ball sustained the total impact energy of 165 375 J without destruction. These balls during their operation do not break, have uniform deterioration and keep their shape. These properties help to reduce consumption of grinding balls, increase mill productivity and quality of the raw material grinding.
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The company “ENERGOSTEEL” completed the industrial test of grinding balls 40 mm of the fifth group of hardness (DSTU 3499-97) on the basis of one of the largest Ukrainian mining & processing enterprises in July 2016. Tests were carried out jointly by technical experts of the both companies. Grinding balls experimental batch have been loaded in the test mill MSHTS 4500х6000 with the following parameters: internal diameter – 4430 mm; the height of lining plates – 100 mm; lifter height – 83 mm and lifter width – 208mm. The material for grinding was middling product (the original ore hardness 9-11 Scale Protodjakonova). During the test was chosen a method of loading an experimental batch of balls in the mill, not the method “substitution”, because: The test mill was put into operation after overhaul. This method significantly reduces the duration of the test, because excluded the replacement of the grinding media used earlier with the experimental grinding balls. In addition to the specific consumption of grinding media during the industrial experiment also the technological parameters of the section was analyzed. According to the test results, based on obtained technical and technological performance of the test mill and work of the section […]
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At previous article we talked about the kinds of mills and grinding media. We have found that the most effective and widely used grinding media are grinding balls Production of grinding balls is regulated by DSTU 8538: 2015 (DSTU 3499-97). Grinding steel balls for ball mills are made of carbon steel and / or stainless steel. Table 1 shows the specific gravity of carbon and alloy steel. The specific gravity of metal is a physical quantity defined as the ratio of the weight of metal to the volume it occupies. Specific gravity of carbon and alloy steel Name (type of steel) Mark or designation Specific gravity (gr/sm3) Constructive (Structural) carbon high-quality steel 45,50,55,60 7,85 Constructive (Structural) leaf-spring steel 60Г, 65Г, 70Г, 55С2,60С2 7,85 Carbon micro-alloyed steel 76, 76Т, 76Ф, 76Ц 7,85 Constructive (Structural) ball bearing steel ШХ15, ШХ15СГ 7,81 Table 1. Specific gravity of carbon and alloy steel Grinding balls characterized by high hardness, resistance to abrasion. Surface of balls responds poorly to splitting and practically don’t crumble. Grinding balls usually classified into five groups of hardness: The first group includes balls with normal hardness. The second group includes grinding balls with increased hardness. The third group includes balls of […]
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The company “Energosteel” held a trial rental service of 100 mm grinding balls (volume – 100 tons) of high carbon alloy steel in July 2016. Experimental party of grinding balls showed higher hardness values throughout cross section of the ball with a surface hardness 58-60HRC and volumetric hardness – 57-59 HRC. According to a new national quality standard for steel grinding balls (DSTU 8538: 2015) these products comply with the fifth group of hardness. Ball Milling for Mining.
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The testing laboratory of “Energosteel” acquired a new instrument for measuring the hardness of grinding balls – updated combined hardness tester T-UD2. Hardness tester can measure the hardness of steel by scales Rockwell, Brinell and Vickers, as well as to carry out recalculation by the scale Brinell values of the tensile strength for pearlite class of steels. The device has the following advantages: Shock-resistant enclosure that withstands multiple falls from a height of 2 meters. High reliability and long service life expressed in more than 100 000 measurements ultrasonic transducer. Updated combined hardness tester T-UD2 is already included in the State Register of measuring instruments of Ukraine Hardness tester is certified in Europe (CE-certified). Combined hardness tester T-UD2 has an ultrasonic hardness testing method, which is suitable for controlling the hardness of hardened surface layers, thereby improving the quality of surface hardness testing of the grinding balls of Energosteel. An ultrasonic method includes a number of additional features and advantages, namely: Allows to measure the hardness of products of any mass with a thickness of 1 mm, which is inaccessible for dynamic hardness testers. In our case, it is the templates for measuring the bulk hardness of grinding balls with […]
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We have already described the primary processes of enrichment of minerals in mining and processing plants and equipment used in these processes. This article is about machines used in the process of grinding that called mills. Types of grinding mills: Mechanical mills. Destruction of grains and particles of material comes in result of blows grinding media or their abrasive actions. Aerodynamic and pneumomechanical mills. The destruction of pieces is due to the acceleration of the air stream and the subsequent impacts on the fixed armor. Mining and processing plants exclusively used mechanical mills as grinding machines. Mechanical mills classified by: Operating modes – continuous operation mills and batch operation mills; Grinding methods – wet grinding mills and dry grinding mills. According to the principle of operation and construction mills divided into: Drum mills Roller-ring mills Runner mills Disk mills Drum mills classified into a rotating drum mills, vibratory mills and centrifugal mills. Mining and processing plants use rotating drum mills (pic. 1). Depending on the form of the grinding media there are ball mills, rod mills, pebble mills and autogenous grinding mills. Grinding media – iron and steel balls with diameter of 15-120 mm, steel or cast iron cylpebs dimensions […]
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01.07.2016 new standard regulating the quality of grinding balls DSTU 8538: 2015 entered into force. In order to understand how to changed the requirements for the production of grinding balls, we decided to display them in a comparative table: 1. CLASSIFICATION AND DIMENSIONS DSTU 3499-97 Rated diameter, mm Nominal diameter, mm Limit deviations from the nominal diameter, mm Volume, сm3 Weight, кг 15 20 25 15,0 20,0 25,0 ± 1,0 1,76 4,18 8,18 0,014 0,033 0,064 30 35 40 45 31,5 36,5 41,5 46,5 ± 2,0 16,4 25,4 37,4 52,6 0,128 0,199 0,294 0,413 50 60 70 80 52,0 62,0 73,0 83,0 ± 3,0 74,0 125,0 204,0 299,0 0,580 0,980 1,600 2,350 90 100 94,0 104,0 ± 4,0 435,0 589,0 3,410 4,620 110 120 114,0 125,0 ± 5,0 776,0 1023,0 6,090 8,030 Note: 1. Deviations from the ball geometric form shall not exceed limit deviations from the nominal diameter. Note: 2. Calculation of ball volume and weight is performed using values of nominal diameter provided that the steel density is 7.85 g / cm3. DSTU 8538:2015 Claim 4 Table 1 without the calculated data that are presented in Attachment A Rated diameter, mm Nominal diameter, mm Limit deviations from […]
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The company “Energosteel” offers to customers products of European quality that has no analogues in Ukraine and CIS. We are talking about grinding balls of increased volumetric hardness and the fifth group of hardness, which production was launched by our factory in 2013. These products had already positively proved themselves in a number of enterprises in Ukraine and abroad. As a result of using these grinding balls achieved flow reduction by at least 20-30% compared to the balls of the 4th group of hardness. Grinding balls of the 5th group hardness have not only a high hardness on the surface, but also a high volumetric hardness that ensures uniform deterioration and shape retention during operating period. For example, we present hardness values over the entire section of the ball. Grinding balls 40mm: Hardness of the cross section, HRC Surface 0,25R 0,5R 0,75R center Volume 65-66 63,5-64 63,5-64 63-64 63-64 64 In addition, the grinding balls produced in steel with a unique chemical composition – higher carbon and other alloyed elements to provide hardwearing ball. Elaboration of the production technology of grinding balls of the 5th group of hardness took us six months because rather complicated technological task […]
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